Quotable (#215)

A life-gripped planet:

By controlling the chemical state of the atmosphere, life has also altered the rocks it comes into contact with, and so oxygenated the crust and mantle of Earth. This changes the material properties of the rocks, how they bend and break, squish, fold, and melt under various forces and conditions. All the clay minerals produced by Earth’s biosphere soften Earth’s crust—the crust of a lifeless planet is harder—helping to lubricate the plate tectonic engine. The wetness of Earth seems to explain why plate tectonics has persisted on Earth and not on its dry twin, Venus. One of the more extreme claims of the Gaia camp, at present neither proven nor refuted, is that the influence of life over the eons has helped Earth hold on to her life‐giving water, while Venus and Mars, lifeless through most of their existence, lost theirs. If so, then life may indeed be responsible for Earth’s plate tectonics. One of the original architects of plate tectonic theory, Norm Sleep from Stanford, has become thoroughly convinced that life is deeply implicated in the overall physical dynamics of Earth, including the “nonliving” interior domain. In describing the cumulative, long-term influence of life on geology, continent building, and plate tectonics, he wrote, “The net effect is Gaian. That is, life has modified Earth to its advantage.” The more we study Earth, the more we see this. Life has got Earth in its clutches. Earth is a biologically modulated planet through and through. In a nontrivial way, it is a living planet.

An Extended Kardashev Scale

Understandably, it’s not very detailed. But here we go:

A type 3 civilization is of another order of evolution altogether, probably taking 100,000 years or longer to get there. Kardashev saw it as “a civilization in possession of energy on the scale of its own galaxy”. […] … What’s next after such an advancement? Kardashev didn’t see a need to hypothesize any further civilizations, but prognosticators since then have proposed that a type 4 world would be able to harness the energy of an entire universe, while a type 5 can do the same in a multiverse, drawing power from multiple universes. […] What about type 6? We are talking god stuff here, controlling time and space, creating universes at will. Type 7? We can’t even imagine and understand what that could be like. …

(It’s hard to be confident about why Type 7 needed tacking on.)

Simplified Drake

Drake equation

Great Filter calculation proceeds, around the back:

… according to a new paper published in the journal Astrobiology, recent discoveries of exoplanets combined with a broader approach to answering this question has allowed researchers to conclude that, unless the odds of advanced life evolving on a habitable planet are immensely low, then humankind is not the universe’s first technological, or advanced, civilization. […] “The question of whether advanced civilizations exist elsewhere in the universe has always been vexed with three large uncertainties in the Drake equation,” said Adam Frank, professor of physics and astronomy at the University of Rochester and co-author of the paper, in a press release. […] … “Thanks to NASA’s Kepler satellite and other searches, we now know that roughly one-fifth of stars have planets in ‘habitable zones,’ where temperatures could support life as we know it. So one of the three big uncertainties has now been constrained,” explained Frank.

Thing is:

However, the universe is more than 13 billion years old. “That means that even if there have been a thousand civilizations in our own galaxy, if they live only as long as we have been around — roughly ten thousand years — then all of them are likely already extinct,” explained Sullivan. “And others won’t evolve until we are long gone.”

(Apologies for the image quality — stumped in my search for a better one.)

Fermi Paradox

It’s worse than you thought:

The Fermi paradox is the discrepancy between the strong likelihood of alien intelligent life emerging (under a wide variety of assumptions), and the absence of any visible evidence for such emergence. In this paper, we extend the Fermi paradox to not only life in this galaxy, but to other galaxies as well. We do this by demonstrating that traveling between galaxies – indeed even launching a colonisation project for the entire reachable universe – is a relatively simple task for a star-spanning civilization, requiring modest amounts of energy and resources. We start by demonstrating that humanity itself could likely accomplish such a colonisation project in the foreseeable future, should we want to, and then demonstrate that there are millions of galaxies that could have reached us by now, using similar methods. This results in a considerable sharpening of the Fermi paradox.


More recent Fermi Paradox sharpening here.

Descending from the abstract plane, there’s this slender thread to hang on to.


Conceived as computational hardware, the scale of the universe sheds awesomeness fast:

The entire visible universe since the big bang is capable of having performed 10^122 operations and of storing 10^92 bits. While these are large numbers, they are still quite finite. 10^122 is roughly 2^406, so the entire universe used as a massive quantum computer is still not capable of searching through all combinations of 500 bits.
This limitation is good news for our ability to design infrastructure today that will still constrain future superintelligences. Cryptographic systems that require brute force searching for a 500 bit key will remain secure even in the face of the most powerful superintelligence. In Base64, the following key:
would stymie the entire universe doing a brute force search.

Quotable (#104)

Bakker’s latest, beginning with one of the greatest uses of a Kant citation I have ever seen, is as relentlessly realistic as always. Here’s the re-statement of the basic BBT orientation it includes:

Blind Brain Theory begins with the assumption that theoretically motivated reflection upon experience co-opts neurobiological resources adapted to far different kinds of problems. As a co-option, we have no reason to assume that ‘experience’ (whatever it amounts to) yields what philosophical reflection requires to determine the nature of experience. Since the systems adapted to discharge far different tasks, reflection has no means of determining scarcity and so generally presumes sufficiency. It cannot source the efficacy of rules so rules become the source. It cannot source temporal awareness so the now becomes the standing now. It cannot source decisions so decisions (the result of astronomically complicated winner-take-all processes) become ‘choices.’ The list goes on.